To reply to a digest, insert the relevant message header; don't reply to the digest header ------------------------------------------------------------- The fourth of the four half-hour broadcasts is dominated by evolutionary psychology more than physiology, diet, activity patterns and simple natural selection. Again, climate change is invoked to explain further steps in human evolution. This time it is the ice age 150,000 to 110,000 years ago which affected Homo heidelbergensis quite differently in their two geographic centres. But first there is a scene from Europe 500,000 years ago: H. heidelbergensis in Europe attacking an Irish stag whose huge swinging antlers concuss one of the hunters who eventually dies. For Winston, the key lesson from this scene is that the body of the dead hunter is abandoned. The absence of respect for the corpse shows that heidelbergensis were not fully human. The hunters were extraordinarily brave by our standards - most trips to the butcher's was a matter of life and death. The book tells us that some of the surviving skeletons show signs of bone disease, infection from broken teeth and malnourishment, but they were characteristically thick- boned and muscular, massively built and fearsomely strong. Their hunts required agility, determination and ability to throw spears and use shorter stabbing spears for the kill. In Eurasia the ice age was freezing erstwhile pastures and reducing the amount of land available for grazing animals (for human nutrition) and human habitation. Survival was achieved by abandonment of the most inhospitable lands but also through adaptation to the encroaching cold. Those who survived when the temperature fell to minus 30 degrees had stocky compact bodies, less than 165cm in height (about 15cm less than heidelbergensis), relatively short limbs to keep in valuable heat. They were the neanderthals and their toughness is illustrated in a memorable sequence where a hunter tumbles down a steep slope and dislocates his finger. He quickly snaps it back into place! Life was tough at the frozen margin. The book tells us that the floor of their living area was filthy. It also explains how the cold > scarce food > small group size > strong relationships. The images of neanderthals surprised me as I have been brought up with a picture in my mind which I now realize was a relict of the Victorian controversy after Darwin - a controversy in which the depiction of all predecessors of H. sapiens as simian thugs served one side (the losing side!) of the debate. An unforgettable and useful corrective. Meanwhile, back in Africa, the ice age has not lowered temperatures in the tropics; its effect is primarily drought, caused by the locking up of water in the huge polar ice caps. While the neanderthals were surviving in the freezing north, the other heidelbergensis descendants were dying, their numbers reduced to possibly a few thousands. Only the very smartest and most resilient made it through this natural selection bottleneck. Winston illustrates the force driving Homo sapiens' survival was their imagination and foresight and how these qualities were what brought them through the 1,000 generation-long drought. There is a brief reference to competition between sapiens and neaderthalensis in which Winston makes the point that in such a competition, the loser doesn't necessarily have to fail, just succeed a little less often. The show ends with Cro-Magnon cave paintings: the paintings depicted something that existed in the imagination of the artists: 'they lived not only in caves, but in an imagined world of their own minds'. I found this fourth episode stimulating but not as informative as the earlier three programs. Winston does a first rate job at presenting humans as just another species, struggling to survive. I would have chosen different scenarios to illustrate what marks Homo sapiens sapiens from its predecessors, so the program put me in a position of having to apply constructive criticism. I see that Winston's recent book 'Human Instinct' has been favourably reviewed and that reflects the development of his own thoughts. These popular programs can do a lot to help others come to grips with the rationale for Evolutionary Fitness. Let your friends know when it is screening in your area. Keith ----------------------------------------------------------------- The FAQ for Evolutionary Fitness is at http://www.evfit.com/faq.htm To unsubscribe from the list send an e-mail to [log in to unmask] with the words SIGNOFF EVOLUTIONARY-FITNESS in the _body_ of the e-mail.